Answer:
the answer is 4
Step-by-step explanation:
if y=21 the we substitute in the main equation
21=8x-11
8x=32
x=4
Here is the equation:
43.25 = 1.25t + 7 where t is the number of minutes he was on the trampoline.
h = -4.9t^2 + vt
In our problem,
v = 12
t = 2
Let's plug our numbers into the equation.
h = -4.9(2)^2 + (12)(2)
h = -19.6 + 24
h = 4.4 m
Quadratic equation: ax² + bx + c =0
x' = [-b+√(b²-4ac)]/2a and x" = [-b-√(b²-4ac)]/2a
6 = x² – 10x ; x² - 10x -6 =0
(a=1, b= - 10 and c = - 6
x' = [10+√(10²+4(1)(-6)]/2(1) and x" = [10-√(10²+4(1)(-6)]/2(1)
x' =5+√31 and x' = 5-√31
factor 1 = x
factor 2 = x - 5
(factor 1) * (factor 2) = 84
(x) * (x - 5) = 84
x² - 5x = 84
x² - 5x - 84 = 0
(x - 12) (x + 7) = 0
x - 12 = 0 or x + 7 = 0
x = 12 or x = -7
factor 2 = x - 5 = (12) - 5 = 7 or (-7) - 5 = -12
Answer: 12, 7 or -7, -12